Can you specify what features you are talking about and also what some of these other smartphones are?
Maggie
Well the biggest feature you are paying for of course is internet access, so if you don't or won't use the interenet much on the phone then you probably don't need a phone where internet access is nonnegotiable.
Other feautres are the gps/maps, notepad, the app store (games, books, social networking, music, etc. there are a ton of apps for all different things), then their is the ipod feature which is an extra that maybe some people won't use if they already have an ipod.
Other smartphones (blackberry, palm, blackjack, moto Q, HTC, etc.) which you may or may not have to purchase hefty data plans with, could be an option if you are just looking for a phone with smartphone details but don't care as much for the "wow" factor of the iphone (organization over fun, I guess).
Either way, iphone or traditional smartphone, they are all good phones just depending on what you are looking for and how much you are looking to put into it.